NeXus is developed as an international standard by scientists and programmers representing major scientific facilities in Europe, Asia, Australia, and North America in order to facilitate greater cooperation in the analysis and visualization of neutron, x-ray, and muon data.

NIAC2011 CodeCamp

Purpose

Develop NeXus software components through intense effort by small groups
working on specific projects and tasks. It is expected that those
attending the 2011 NeXus Code Camp will already have strong foundation
and understanding in aspects of the NeXus software and come ready with
knowledge, tools, and ideas to make significant progress during the
event. The specific projects and tasks, as well as the list of
participants, are described on this wiki and will be revised as the
event draws near.

APS Visitor registration

You must register as an APS Visitor in advance (to identify matters
related to Passport, Visa, and ANL Site Access) or you should not expect
access to the ANL site. If asked, indicate that you are visiting Pete
Jemian.

For the paperwork of all international visitors, we need each degree,
year earned, and institution name. Additionally for certain visas, we
need additional information:

F1 visa: we need the I-20 number and expiration date.
J1 visa: we need the DS-2019 number and expiry date.
H1 visa: we need the I797 number and expiry date.

Presentations

… coming …

Final Report

As some of you might know, the NeXus technical subcommittee and
especially Pete Jemian have invested a lot of work to update the NeXus
manual in the last year. It is now current and much better then it used
to be. In this work we arrived at a major milestone on our last code
camp in Chicago, October 20 - 22. Now, the NeXus WWW site has received a
new front page and its content is created from the NeXus manual. Though
not all of it looking as beautiful as it could be, at least the content
is correct and up to data.

Another good news is that we had some discussions with the detector
manufacturer Dectris. They do the Mythen, Pilatus and Eiger detectors.
With the Eiger detector they will start writing HDF-5 files with NeXus
conventions. The programming model will be that Dectris writes the
detector data and the local DAQ system adds further meta data to the
HDF-5 NeXus file. In order to support this, some more fields have been
added to NXdetector.

Other things which we addressed during the code camp:

For HDF-5 all dimensions can now be unlimited

NAPI was moved from HDF-5 1.6 to HDF-5 1.8 which is now current.
Support for HDF-5 1.6 was stopped two years ago.

A set of additional API functions was defined which allow to use 64
bit integers for the dimensions.

Some more manual work was done: there will be examples how to write
NeXus files with the HDF-5 API alone soon. A new manual, NeXus for
the Impatient, is in progress. This is a short introduction to NeXus
in about 10 pages.

Some more work was done to integrate Ray Osborn’s tree python API
and to write more tests for the python interface.

Some progress was made on axis dependency encoding

We will gradually move from autotools to cmake for the NeXus API.

We had some discussions on a new C++ tree API to be written by Eugen
Wintersberger, on a parallel HDF driver for NeXus, and a possible
move to sphinx for the NeXus manual.

All in all, we managed to put a man-month of work into NeXus between the
seven of us who attended the code camp. Many thanks to everyone who
participated and to Pete Jemian who did a wonderful job as a local
organiser. [PRJ: I thank all of you.]

We are in good hope that a new version of the NeXus-API will be released
before the end of this year. We also strive to make a 1.0 release of the
NeXus application definitions by then.

Best Regards, Mark Koennecke

Added note

We also has a good discussion with scientists and staff of the APS
regarding the release of details of how NeXus is implemented in HDF5.
Also discussed were current APS plans to store data in HDF5 files but,
for performance reasons as well as simplicity, not necessarily in
compliance with NeXus.